Loom roll cover material



T. M. KNOWLAND ETAL LOOM ROLL COVER MATERIAL INVENTOR.

{Au a/$44! #70414 Nov. 8, 1955 Filed Sept. 30. 1954 United States Patent 2,722,730 LOOM ROLL COVER MATERIAL Thomas M. Knowland, Belmont, and Carl R. Stable, Roslindale, Mass., assignors to Boston Woven Hose and Rubber Company, Cambridge, Mass, a corporation of Massachusetts Application September 30, 1954, Serial No. 459,429 2 Claims. (Cl. 2880) This invention comprises a new and improved loom roll cover material presenting an operating or traction surface of novel and very desirable characteristics.

Looms in general are equipped with take-off mechanism for removing the woven fabric from the loom at the same rate that it is formed by the weaving mechanism. Ordinarily this take-01f mechanism includes a roll which may be 8" to 16" in diameter and which has its surface covered with sheet material having a high coefficient of friction. The roll is driven at a speed consistent with the rate of weaving and is ordinarily provided with auxiliary snub rollers so that the woven fabric may be snubbed around a substantial arc of the take-off roll which then serves to pull the woven fabric through the loom. The tension required to pull the woven fabric through the loom against the resistance of the creel, warp beam and other loom parts is very considerable so that the loom take-off roll surface must in practice develop a high coefficient of friction with the cloth with which it is to deal.

Materials most used for loom roll surface consist of a ply of textile sheeting coated with rubber or resilient plastic which may be from .050" to .125" thick, the rubber surface having a roughened, scored or embossed surface. Heretofore it has been diflicult to produce a surface having adequate friction or traction characteristics without making it so coarse or rough as locally to indent the surface of delicate fabrics which may be woven and which have their surface adversely affected by any surface imprint imparted by the take-ofi roll. Such imprints are sometimes called star marks. One of the most successful surfaces heretofore employed is the so-called sandpaper finish as described in U. S. Patent No. 2,156,871 May 2, 1939. A serious difiiculty of all such random pattern surfaces developed from sandpaper, crepe rubber or the like is the tendency of certain areas to contain local areas of higher friction or greater height than other areas so that local stresses and consequently objectionable indentations appear in the woven fabric.

The present invention is based on the discovery that the difficulties inherent to the use of a random pattern take-off material may be avoided by employing the uniform pattern of ribs all running in the same direction and each rib having transversely offset sections of the same length and same regular longitudinal spacing, the said offset sections being staggered in adjacent ribs and thus forming alternate wide and narrow spaces between the ribs and defining a multiplicity of individual resilient tongues for engagement with the woven fabric. Such a surface may be produced as the negative imprint upon rubbery or plastic composition of a square duck fabric or against a positive plastic mold produced from a negative plastic mold which, in turn, has been molded in contact with the duck surface.

This new type of loom roll cover has many advantages over those heretofore known since it can be produced in patterns of absolutely uniform surface configuration and with a selected degree of coarseness and corresponding coefficient of friction. Such a pattern presents an almost infinite number of individual resilient contact tongues distributed with precise uniformity thus insuring identical treatment to every area of the woven fabric.

These and other advantages and characteristics of the invention will be best understood and appreciated from the following description of a preferred embodiment 2,722,730 Patented Nov. 8, 1955 thereof selected for purposes of illustration and shown in the accompanying drawings in which:

Fig. 1 is a plan view of a piece of my novel loom roll cover material,

Fig. 2 is a similar view on a very greatly enlarged scale, and

Fig. 3 is a fragmentary view in perspective on a less enlarged scale.

The illustrated material comprises a backing sheet 10 of close woven fabric to which is permanently attached a layer 11 of resilient rubber composition or plastic ma terial. The surface of this material is molded and cured or vulcanized by heat and pressure contact with a coarse square woven duck and presents a series of ribs 12 all running in the same direction and each being interrupted by transversely offset sections 13 of the same length and same regular longitudinal spacing. These offset sections are staggered in adjacent ribs and thus form alternate wide spaces 14 and narrow spaces 15 between the ribs and define a multiplicity of individual resilient tongues 16. Each of these tongues has a substantially straight horizontal top edge and curved or filleted ends, and all of these tongues terminate in a common plane. It will be seen, therefore, that when the woven cloth is wound around a drum surface of this character, the tongues 16 engage it uniformly over its entire area with a clinging resilient touch which develops a high uniform coefiicient of friction and is effective to advance the fabric without any distortion Whatever. In effect the tongues present a multiplicity of squeegee edges acting in concert to advance the fabric.

The precise composition of the layer 10 is of secondary importance so long as it is tough, resilient and elastic. Any one of a number of compounds based on natural or synthetic rubbers may be successfully used. A typical compound based on natural rubber is compounded as follows:

Having thus disclosed our invention and described in detail an illustrative embodiment thereof, we claim as new and desire to secure by Letters Patent:

1. A loom roll cover comprising a backing sheet of close woven fabric having a gripping layer of resilient material presenting a uniform pattern of ribs all running in the same direction and each rib having transversely offset sections of the same length and same regular longitudinal spacing, the said offset sections being staggered in adjacent ribs and thus forming alternate wide and narrow spaces between the ribs, and defining a multiplicity of individual resilient tongues.

2. A loom roll cover as described in claim 1 further characterized by the fact that the said ribs and the resilient tongues formed thereby all terminate in a common plane.

References Cited in the file of this patent UNITED STATES PATENTS 1,534,527 Joseph Apr. 21, 1925 1,865,345 Wheatley June 28, 1932 2,156,871 Rittenhouse May 2, 1939 

